1. Field of the Invention
The present invention relates to a band-blade cutting tool which is used for cutting a band blade that is a so-called Thomson blade, and also to a band-blade working apparatus having a function of cutting such a band blade into a predetermined shape and like functions.
2. Description of the Prior Art
As shown in FIGS. 12A and 13, a band blade 1 which is a so-called Thomson blade has an sharp blade portion 13 in one edge in the width direction of a strip-like ridge portion 12. The band blade 1 is subjected to necessary workings and then used in, for example, formation of breaks or a fold in a paper piece, a paper sheet, a wood piece, or the like. In addition to working the band blade 1 to form it into a predetermined shape, workings which may be applied to the band blade 1 include: working of punching given portions of the ridge portion 12 of the band blade 1 into a rectangular shape to form bridges 14 in the ridge portion 12 as shown in FIG. 12B; and that of cutting away the bridges 14 as shown in FIG. 12C. The cutting of the bridges 14 may be conducted by, for example, so-called miter cutting in which, as shown in the XIVa portion in FIG. 12C and in FIG. 14A, the blade portion 13 is obliquely crossly cut so that one cut end 13a has the same inclination angle .theta.2 as the inclination angle .theta.1 (see FIG. 13) of the side face of the blade portion 13, or so-called straight cutting in which, as shown in the XIVb portion in FIG. 12C and in FIG. 14B, the blade portion 13 is cut perpendicular to the blade edge so that both cut ends 13c have a straight end face. As shown in FIG. 15, for example, the band blade 1 which has undergone miter cutting is placed so that the cut end 13a of the blade portion 13 is tightly butted against a side face of a blade portion 13' of another band blade 1' serving as a counter member.
Conventionally, when miter cutting and straight cutting are to be executed, different band-blade cutting tools each having a cutting blade of a shape corresponding to miter cutting or straight cutting are used.
However, execution of miter cutting and straight cutting by using different band-blade cutting tools has a drawback in that different mechanisms for respectively driving the band-blade cutting tools must be separately prepared. When such a band-blade cutting tool is incorporated into a band-blade working apparatus having functions such as that of bending a band blade so that the apparatus is further provided with a cutting function, the number of incorporated band-blade cutting tools is increased, thereby producing a problem in that the increased number of band-blade cutting tools impedes miniaturization of a band-blade working apparatus.